Generally, a mobile communication system has been developed to provide a voice service while securing an activity of a user. However, the mobile communication system gradually extends an area from a voice service to a data service. At present, the mobile communication system has been developed to provide a high-speed data service. However, since the existing mobile communication system providing services suffers from a resource shortage phenomenon and users require a higher-speed service, a more developed mobile communication system has been required.
Meanwhile, unlike a voice service, a data service determines resources, and the like, which may be allocated depending on the amount of data to be transmitted and a channel condition. Therefore, in a wireless communication system such as the mobile communication system, a scheduler performs management such as allocating a transmission resource in consideration of the amount of data to be transmitted, the channel condition, the amount of data, and the like. This is identically performed even in long term evolution (LTE) which is one of the next-generation mobile communication systems and the scheduler located in a base station manages and allocates a radio transmission resource.
Recently, discussions about an advanced LTE communication system (LTE-advanced (LTE-A)) which increases a transmission rate by combining various new technologies with the LTE communication system have started in earnest. In the LTE-A system, improvement in multimedia broadcast multicast service (MBMS) is also included. The MBMS (used mixed with evolved MBMS (eMBMS) in the present disclosure) is a broadcasting service provided through the LTE system.
In particular, when a public safety-LTE PS-LTE performs group communication using a unicast method, excessive resources are required. Therefore, a method for group communication using eMBMS is used. However, when a packet transmitted from the eMBMS transmission service used in the public safety-LTE PS-LTE is lost, it is difficult to recover the lost packet. Accordingly, when the public safety-LTE PS-LTE uses the eMBMS to provide the group communication service, discussions about a method for securing reliability of group communication are required.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.